| Value | Meaning |
|---|---|
| IPconsts.IPPROTO_IP | default internet protocol (probably 4 for compatibility) |
| IPV4consts.IPPROTO_IP | internet protocol version 4 |
| IPV6consts.IPPROTO_IPV6 | internet protocol version 6 |
| ICMPconsts.IPPROTO_ICMP | internet control message protocol |
| IGMPconsts.IPPROTO_IGMP | internet group management protocol |
| TCPconsts.IPPROTO_TCP | transmission control protocol |
| PUPconsts.IPPROTO_PUP | PARC universal packet protocol |
| UDPconsts.IPPROTO_UDP | user datagram protocol |
| IDPconsts.IPPROTO_IDP | Xerox NS protocol |